Is it really against your consent though? They didn't take the taxes without you knowing. Before any tax is passed or increased the public is notified. So I guess we can take the issue of theft away.
Just because you know, doesn't mean you consented. Governments, regulators and politicians
force you to pay, and if you don't, their partners, the judiciary system comes to the play to punish you. You don't have any alternatives. If it's not theft, it's extortion in the best of the cases...
Taxation becomes wrong when it becomes extreme and when the government don't make good use of the taxes. In my opinion, taxes are like payments to the government so they'll be able to continue providing what they're supposed to provide for their citizens. Where it becomes wrong is when you pay your taxes yet don't get anything in return.
I can't say for every countries, because there must be some civilized socities where taxation works and return good fruits for citizens in general. However, in countries supressed by corruption and lack of ethics, the scenario you described above is the reality 24 hours a day, for decades already. And it doesn't seem it's going to improve anytime soon.
Taxation keeps increasing in order to maintain the status quo of the authorities on the top of the pyramid. And nothing improves for the common citizens who pay the largest portion of the taxes (proportionally speaking). It's totally ethical and legit to do what is in your reach to avoid paying taxes to the government in this case.
Just because something is moral (what means the law or rule itself), doesn't mean it's ethical... Ethics reflect over morals, and if a law isn't ethical, it shouldn't be followed.